A sequential biometric cryptosystem includes: a registration terminal that extracts a set of feature data from each of multiple pieces of biological information acquired from each user, sequentially selects, out of these, a group of multiple sets of feature data, incrementing the number of combined sets, creates a protection template for each selected group of feature data, and stores the protection template into a storage apparatus. The sequential biometric cryptosystem also includes an authentication terminal that extracts feature data from a combination including one or more pieces of biological information of a specified user, acquired through a sensor on the user, verifies a combination of the extracted feature data against the protection template derived from the biological information having the same specified attribute, and performs, if the verification is successful, specified processing on the user.